Comparative analysis of imaging configurations and objectives for Fourier microscopy

Fourier microscopy is becoming an increasingly important tool for the analysis of optical nanostructures and quantum emitters. However, achieving quantitative Fourier space measurements requires a thorough understanding of the impact of aberrations introduced by optical microscopes, which have been optimized for conventional real-space imaging. Here, we present a detailed framework for analyzing the performance of microscope objectives for several common Fourier imaging configurations. To this end, we model objectives from Nikon, Olympus, and Zeiss using parameters that were inferred from patent literature and confirmed, where possible, by physical disassembly. We then examine the aberrations most relevant to Fourier microscopy, including the alignment tolerances of apodization factors for different objective classes, the effect of magnification on the modulation transfer function, and vignetting-induced reductions of the effective numerical aperture for wide-field measurements. Based on this analysis, we identify an optimal objective class and imaging configuration for Fourier microscopy. In addition, as a resource for future studies, the Zemax files for the objectives and setups used in this analysis have been made publicly available.Comment: For related figshare fileset with complete Zemax models of microscope objectives, tube lenses, and Fourier imaging configurations, see Ref. [41] (available at http://dx.doi.org/10.6084/m9.figshare.1481270

Wide-angle energy-momentum spectroscopy

Light emission is defined by its distribution in energy, momentum, and polarization. Here, we demonstrate a method that resolves these distributions by means of wide-angle energy-momentum spectroscopy. Specifically, we image the back focal plane of a microscope objective through a Wollaston prism to obtain polarized Fourier-space momentum distributions, and disperse these two-dimensional radiation patterns through an imaging spectrograph without an entrance slit. The resulting measurements represent a convolution of individual radiation patterns at adjacent wavelengths, which can be readily deconvolved using any well-defined basis for light emission. As an illustrative example, we use this technique with the multipole basis to quantify the intrinsic emission rates for electric and magnetic dipole transitions in europium-doped yttrium oxide (Eu$^{3+}$:Y$_{2}$O$_{3}$) and chromium-doped magnesium oxide (Cr$^{3+}$:MgO). Once extracted, these rates allow us to reconstruct the full, polarized, two-dimensional radiation patterns at each wavelength.Comment: 4 pages, 4 figure

Electroluminescence efficiencies of erbium in silicon-based hosts

International audienceWe report on room-temperature 1.5 lm electroluminescence from trivalent erbium (Er3þ) ionsembedded in three different CMOS-compatible silicon-based hosts: SiO2, Si3N4, and SiNx. We showthat although the insertion of either nitrogen or excess silicon helps enhance electrical conductionand reduce the onset voltage for electroluminescence, it drastically decreases the external quantumefficiency of Er3þ ions from 2% in SiO2 to 0.001% and 0.0004% in SiNx and Si3N4, respectively.Furthermore, we present strong evidence that hot carrier injection is significantly more efficient thandefect-assisted conduction for the electrical excitation of Er3þ ions. These results suggest strategiesto optimize the engineering of on-chip electrically excited silicon-based nanophotonic light sources

Zemax (optical design) files of microscope objectives, tube lenses, and Fourier imaging setups

<p>This fileset contains Zemax files related to the manuscript entitled “Comparative analysis of imaging configurations and objectives for Fourier microscopy” by Jonathan A. Kurvits, Mingming Jiang, and Rashid Zia. Specifically, it includes multi-configuration Zemax files that allow for the comparison of different Fourier microscopy imaging configurations as well as Zemax lens files and lens catalogs for microscope objectives and tube lenses, as inferred from the following published patents:</p> <p>1) U.S. Patent # 5,517,360; assignee: Olympus; objective description: 60x, 1.4 NA Plan Apo.</p> <p>2) U.S. Patent # 5,659,425; assignee: Olympus; objective description: 100x, 1.65 NA Apo.</p> <p>3) U.S. Patent # 6,504,563; assignee: Zeiss; objective description: 100x, 1.45 NA TIRF.</p> <p>4) U.S. Patent # 6,519,092; assignee: Nikon; objective description: 60x, 1.4 NA Plan Apo.</p> <p>5) U.S. Patent # 6,519,092; assignee: Nikon; objective description: 100x, 1.4 NA Plan Apo.</p> <p>6) U.S. Patent # 7,046,451; assignee: Nikon; objective description: 60x, 1.5 NA TIRF (modeled as 1.49 NA to match possible commercial realization).</p> <p>7) U.S. Patent # 7,046,451; assignee: Nikon; objective description: 100x, 1.5 NA TIRF (modeled as 1.49 NA to match possible commercial realization).</p> <p>8) U.S. Patent # 7,889,433; assignee: Nikon; objective description: 60x, 1.25 water immersion.</p> <p> </p> <p><strong>Update</strong> <strong>(9/14/2015, Version 2, filenames annotated with "_v2" suffix):</strong> For all objectives files and the objective catalog, the immersion oil layer semi-diameter has been changed to float so as to prevent unrealistic vignetting that may otherwise occur. Additionally, for all multiconfiguration files, the "before image plane" configuration has been modified. Specifically, the position of the Bertrand Lens has been modified so that it correctly images the BFP image onto the real image plane. In all cases, this required a shift in the position of the Bertrand Lens of ~1cm further from the tube lens. </p> <p> </p> <p><strong>Update (10/19/2015, Description only):</strong> The related paper on “Comparative analysis of imaging configurations and objectives for Fourier microscopy” by Jonathan A. Kurvits, Mingming Jiang, and Rashid Zia has been published in the Journal of the Optical Society of America A [J. Opt. Soc. Am. A 32, 2082-2092 (2015)]. This paper provides a detailed description of how these Zemax models were produced and analyzed. If you use the Zemax models provided here, we would appreciate it if you could cite this paper as well as the figshare fileset. Here is a link to the paper: http://dx.doi.org/10.1364/JOSAA.32.002082</p

ARTICLE Dynamic control of light emission faster than the lifetime limit using VO 2 phase-change

Modulation is a cornerstone of optical communication, and as such, governs the overall speed of data transmission. Currently, the two main strategies for modulating light are direct modulation of the excited emitter population (for example, using semiconductor lasers) and external optical modulation (for example, using Mach-Zehnder interferometers or ring resonators). However, recent advances in nanophotonics offer an alternative approach to control spontaneous emission through modifications to the local density of optical states. Here, by leveraging the phase-change of a vanadium dioxide nanolayer, we demonstrate broadband all-optical direct modulation of 1.5 mm emission from trivalent erbium ions more than three orders of magnitude faster than their excited state lifetime. This proof-of-concept demonstration shows how integration with phase-change materials can transform widespread phosphorescent materials into high-speed optical sources that can be integrated in monolithic nanoscale devices for both free-space and on-chip communication

Dynamic control of light emission faster than the lifetime limit using VO2 phase-change

Modulation is a cornerstone of optical communication, and as such, governs the overall speed of data transmission. Currently, the two main strategies for modulating light are direct modulation of the excited emitter population (for example, using semiconductor lasers) and external optical modulation (for example, using Mach–Zehnder interferometers or ring resonators). However, recent advances in nanophotonics offer an alternative approach to control spontaneous emission through modifications to the local density of optical states. Here, by leveraging the phase-change of a vanadium dioxide nanolayer, we demonstrate broadband all-optical direct modulation of 1.5 μm emission from trivalent erbium ions more than three orders of magnitude faster than their excited state lifetime. This proof-of-concept demonstration shows how integration with phase-change materials can transform widespread phosphorescent materials into high-speed optical sources that can be integrated in monolithic nanoscale devices for both free-space and on-chip communication

Reusable Inorganic Templates for Electrostatic Self-Assembly of Individual Quantum Dots, Nanodiamonds, and Lanthanide-Doped Nanoparticles

In this paper, we present an electrostatic self-assembly method for the controlled placement of individual nanoparticle emitters based on reusable inorganic templates. This method can be used to integrate quantum emitters into nanophotonic structures over macroscopic areas and is applicable to a variety of patterning materials and emitter systems. By utilizing surface-charge-mediated self-assembly, highly ordered arrays of nanoparticle emitters were created. To illustrate the broad applicability of this technique, we demonstrate self-assembly using colloidal quantum dots (QD), nitrogen vacancy (NV) centers in diamond nanoparticles, and lanthanide-doped upconversion nanoparticles (UCNP). Placement of single QDs and NV centers was confirmed by performing photon antibunching measurements using a Hanbury-Brown Twiss setup. In addition, template reusability was demonstrated through daily redeposition experiments over a one month period

A Phase II Study to Evaluate the Safety and Efficacy of Prasinezumab in Early Parkinson's Disease (PASADENA) : Rationale, Design, and Baseline Data

Altres ajuts: F. Hoffmann-La Roche Ltd.Background: Currently available treatments for Parkinson's disease (PD) do not slow clinical progression nor target alpha-synuclein, a key protein associated with the disease. Objective: The study objective was to evaluate the efficacy and safety of prasinezumab, a humanized monoclonal antibody that binds aggregated alpha-synuclein, in individuals with early PD. Methods: The PASADENA study is a multicenter, randomized, double-blind, placebo-controlled treatment study. Individuals with early PD, recruited across the US and Europe, received monthly intravenous doses of prasinezumab (1,500 or 4,500 mg) or placebo for a 52-week period (Part 1), followed by a 52-week extension (Part 2) in which all participants received active treatment. Key inclusion criteria were: aged 40-80 years; Hoehn & Yahr (H&Y) Stage I or II; time from diagnosis ≤2 years; having bradykinesia plus one other cardinal sign of PD (e.g., resting tremor, rigidity); DAT-SPECT imaging consistent with PD; and either treatment naïve or on a stable monoamine oxidase B (MAO-B) inhibitor dose. Study design assumptions for sample size and study duration were built using a patient cohort from the Parkinson's Progression Marker Initiative (PPMI). In this report, baseline characteristics are compared between the treatment-naïve and MAO-B inhibitor-treated PASADENA cohorts and between the PASADENA and PPMI populations. Results: Of the 443 patients screened, 316 were enrolled into the PASADENA study between June 2017 and November 2018, with an average age of 59.9 years and 67.4% being male. Mean time from diagnosis at baseline was 10.11 months, with 75.3% in H&Y Stage II. Baseline motor and non-motor symptoms (assessed using Movement Disorder Society-Unified Parkinson's Disease Rating Scale [MDS-UPDRS]) were similar in severity between the MAO-B inhibitor-treated and treatment-naïve PASADENA cohorts (MDS-UPDRS sum of Parts I + II + III [standard deviation (SD)]; 30.21 [11.96], 32.10 [13.20], respectively). The overall PASADENA population (63.6% treatment naïve and 36.4% on MAO-B inhibitor) showed a similar severity in MDS-UPDRS scores (e.g., MDS-UPDRS sum of Parts I + II + III [SD]; 31.41 [12.78], 32.63 [13.04], respectively) to the PPMI cohort (all treatment naïve). Conclusions: The PASADENA study population is suitable to investigate the potential of prasinezumab to slow disease progression in individuals with early PD. Trial Registration: NCT03100149